In this occurrence, the pilot of C-FBVW had given the only available radio headset to his passenger and had delegated the operation of the aircraft radio to her. By doing so, the pilot gave up any ability he had to monitor the ATF directly, and, by doing so, he reduced the effectiveness of the established radio protocols as a defence to support the see and avoid principle. The pilot of C-GWAC used a handheld radio to transmit his position and intention when he entered the ATF area. Based on a post-crash examination of that radio, it was determined that the radio (as found) was not on the appropriate ATF. Although this examination cannot confirm what frequency was selected at the time the aircraft entered the ATF area, it is known that neither the pilot of C-GWAC nor the passenger of C-FBVW heard any radio transmissions from the other aircraft. The cause for the incorrect frequency selection is not known, but it is possible that a frequency selection or scan button may have inadvertently activated after the pilot put the radio in his shirt pocket. Once the radio was de-tuned from the correct ATF, then any transmission made by the pilot of C-GWAC would have been ineffective in alerting other aircraft in the area of his presence. Similarly, any transmissions made by other aircraft in the area would not have been received by the pilot of C-GWAC. The pilot of C-FBVW was conducting left-hand traffic patterns to runway 32 at 108 Mile Airport, whereas the CFS states right-hand circuits should be flown to runway 32. By not following the published circuit procedure, this pilot increased the risk of an in-flight collision. Additionally, while in the downwind leg, and during the final turn, his ability to see the conflicting traffic would have been impaired by visual interference from the cockpit dash, the aircraft's engine section, and the passenger. The result was that the visual search procedure used by the occupants of C-FBVW was ineffective. The pilot of C-GWAC had made a radio call prior to entering the ATF area and had not heard any response from other aircraft. He therefore concluded no other aircraft were in the area and continued to the airport for a straight-in approach to runway 32. This circuit-joining procedure is not recommended when operating in an ATF area. During the approach, the pilot of C-GWAC concentrated his lookout upward and to the right in anticipation of any unannounced traffic operating in a right-hand traffic pattern. This visual search procedure was ineffective because the opposing traffic was operating in a left-hand pattern and approached from above and to the pilot's left side. C-FBVW was equipped with navigation lights and a landing light, neither of which were selected on at the time of the collision. The non-use of available lighting systems reduces the visual conspicuousness of an aircraft and thereby increases the risk of it not being seen by other pilots. C-GWAC was equipped with navigation lights, a rotating anticollision beacon, and a landing light. The navigation lights and rotating anticollision beacon were on at the time of the collision, but the landing light was off. Because neither pilot detected the potential collision, neither took avoidance action prior to the collision.Analysis In this occurrence, the pilot of C-FBVW had given the only available radio headset to his passenger and had delegated the operation of the aircraft radio to her. By doing so, the pilot gave up any ability he had to monitor the ATF directly, and, by doing so, he reduced the effectiveness of the established radio protocols as a defence to support the see and avoid principle. The pilot of C-GWAC used a handheld radio to transmit his position and intention when he entered the ATF area. Based on a post-crash examination of that radio, it was determined that the radio (as found) was not on the appropriate ATF. Although this examination cannot confirm what frequency was selected at the time the aircraft entered the ATF area, it is known that neither the pilot of C-GWAC nor the passenger of C-FBVW heard any radio transmissions from the other aircraft. The cause for the incorrect frequency selection is not known, but it is possible that a frequency selection or scan button may have inadvertently activated after the pilot put the radio in his shirt pocket. Once the radio was de-tuned from the correct ATF, then any transmission made by the pilot of C-GWAC would have been ineffective in alerting other aircraft in the area of his presence. Similarly, any transmissions made by other aircraft in the area would not have been received by the pilot of C-GWAC. The pilot of C-FBVW was conducting left-hand traffic patterns to runway 32 at 108 Mile Airport, whereas the CFS states right-hand circuits should be flown to runway 32. By not following the published circuit procedure, this pilot increased the risk of an in-flight collision. Additionally, while in the downwind leg, and during the final turn, his ability to see the conflicting traffic would have been impaired by visual interference from the cockpit dash, the aircraft's engine section, and the passenger. The result was that the visual search procedure used by the occupants of C-FBVW was ineffective. The pilot of C-GWAC had made a radio call prior to entering the ATF area and had not heard any response from other aircraft. He therefore concluded no other aircraft were in the area and continued to the airport for a straight-in approach to runway 32. This circuit-joining procedure is not recommended when operating in an ATF area. During the approach, the pilot of C-GWAC concentrated his lookout upward and to the right in anticipation of any unannounced traffic operating in a right-hand traffic pattern. This visual search procedure was ineffective because the opposing traffic was operating in a left-hand pattern and approached from above and to the pilot's left side. C-FBVW was equipped with navigation lights and a landing light, neither of which were selected on at the time of the collision. The non-use of available lighting systems reduces the visual conspicuousness of an aircraft and thereby increases the risk of it not being seen by other pilots. C-GWAC was equipped with navigation lights, a rotating anticollision beacon, and a landing light. The navigation lights and rotating anticollision beacon were on at the time of the collision, but the landing light was off. Because neither pilot detected the potential collision, neither took avoidance action prior to the collision. The see and avoid principle was ineffective as a method of separating aircraft because neither pilot saw the other aircraft prior to the in-flight collision. The pilot of C-FBVW was conducting left-hand traffic patterns to runway 32 at 108 Mile Airport whereas right-hand traffic patterns were published. The pilot of C-GWAC conducted a straight-in approach to runway 32 rather than using the recommended circuit joining procedure, thereby reducing the opportunity to be seen by other traffic. The pilot of C-GWAC used a handheld radio to transmit his position and intention prior to entering the ATF area. However, based on a post-crash examination of that radio, it appears likely that the radio was not on the appropriate ATF.Findings as to Causes and Contributing Factors The see and avoid principle was ineffective as a method of separating aircraft because neither pilot saw the other aircraft prior to the in-flight collision. The pilot of C-FBVW was conducting left-hand traffic patterns to runway 32 at 108 Mile Airport whereas right-hand traffic patterns were published. The pilot of C-GWAC conducted a straight-in approach to runway 32 rather than using the recommended circuit joining procedure, thereby reducing the opportunity to be seen by other traffic. The pilot of C-GWAC used a handheld radio to transmit his position and intention prior to entering the ATF area. However, based on a post-crash examination of that radio, it appears likely that the radio was not on the appropriate ATF. The pilot of C-FBVW had given the only available radio headset to his passenger and had delegated the operation of the aircraft's radio to her. By doing so, the pilot gave up any ability he had to monitor the ATF directly. Neither pilot was using all available aircraft lighting systems to increase the visual conspicuousness of his aircraft.Findings as to Risk The pilot of C-FBVW had given the only available radio headset to his passenger and had delegated the operation of the aircraft's radio to her. By doing so, the pilot gave up any ability he had to monitor the ATF directly. Neither pilot was using all available aircraft lighting systems to increase the visual conspicuousness of his aircraft. A review of mid-air collisions occurring between August 1989 and August 1999 indicates that there were 17 accidents of this type in Canada during this 10-year period. Of these accidents, 8 involved some form of formation flight. Of the remaining 9 accidents, 3 occurred in practice training areas and 6 occurred in the vicinity of uncontrolled airports between aircraft that were not associated with each other. Following a mid-air collision on 01 May 1995, to improve safety in this area of flight the TSB recommended that: TC responded positively to both recommendations. In 1996, TC published four articles about collision avoidance in issue 2/96 of the Aviation Safety Newsletter. Additionally, TC has provided relevant information in A.I.P. CanadaM and has produced and distributed a poster entitled MF/ATF Communications Requirements to highlight and review applicable pilot reporting and communication requirements within MF and ATF areas. More recently, TC has published a series of Human Factors in Aviation manuals, developed a video on procedures to be used at uncontrolled aerodromes, and amended the Flight Instructor Guide to provide more comprehensive training and education in related issues. Recently, there have been three in-flight collisions in British Columbia involving a total of six aircraft and 12 people. All but three of the involved people died in the accidents. With the increasing concerns brought on by these accidents, NAV CANADA developed, and recently began conducting, pilot education sessions on air traffic procedures that are used at controlled and uncontrolled aerodromes. Both the TSB and TC have participated in these sessions to provide information on recent mid-air collisions and on the limitations of human recognition and response. This active program is expected to raise the awareness of operators, owners, and pilots of the importance of using all available equipment and procedures to reduce the risk of an in-flight collision.Safety Action A review of mid-air collisions occurring between August 1989 and August 1999 indicates that there were 17 accidents of this type in Canada during this 10-year period. Of these accidents, 8 involved some form of formation flight. Of the remaining 9 accidents, 3 occurred in practice training areas and 6 occurred in the vicinity of uncontrolled airports between aircraft that were not associated with each other. Following a mid-air collision on 01 May 1995, to improve safety in this area of flight the TSB recommended that: TC responded positively to both recommendations. In 1996, TC published four articles about collision avoidance in issue 2/96 of the Aviation Safety Newsletter. Additionally, TC has provided relevant information in A.I.P. CanadaM and has produced and distributed a poster entitled MF/ATF Communications Requirements to highlight and review applicable pilot reporting and communication requirements within MF and ATF areas. More recently, TC has published a series of Human Factors in Aviation manuals, developed a video on procedures to be used at uncontrolled aerodromes, and amended the Flight Instructor Guide to provide more comprehensive training and education in related issues. Recently, there have been three in-flight collisions in British Columbia involving a total of six aircraft and 12 people. All but three of the involved people died in the accidents. With the increasing concerns brought on by these accidents, NAV CANADA developed, and recently began conducting, pilot education sessions on air traffic procedures that are used at controlled and uncontrolled aerodromes. Both the TSB and TC have participated in these sessions to provide information on recent mid-air collisions and on the limitations of human recognition and response. This active program is expected to raise the awareness of operators, owners, and pilots of the importance of using all available equipment and procedures to reduce the risk of an in-flight collision.